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1
Zhao, Rongyong, Ping Jia, Chuanfeng Han, Yan Wang, Cuiling Li et Zhishu Zhang. « Analysis of dynamic model based on pedestrian’s abnormal posture ». MATEC Web of Conferences 355 (2022) : 03010. http://dx.doi.org/10.1051/matecconf/202235503010.
Texte intégralRésumé :
It is significant to detect abnormal postures of pedestrians in the crowd to crowd stability control. This study locates the joint points of pedestrians based on the pose estimation algorithm OpenPose. After the analysis of 18 nodes and six body parts, the sudden value of node acceleration is obtained, which is compared with the acceleration of the pedestrian’s centre of mass. When there is at least one difference in the direction or acceleration value of the two, it means that the pedestrian has abnormal behaviour. Furthermore, this study analyses the result of comparing the change of z-coordinate value in pedestrian movement with 20% of pedestrian height. These two judgment methods together constitute the dynamic criterion of pedestrian abnormal posture, and judge whether the pedestrian has abnormal behaviour. Compared with the previous dynamic analysis of pedestrian abnormal posture, the accuracy of abnormal posture judgment is improved. This provides a theoretical basis for crowd stability analysis.
2
Zhu, Nuo, Bin Jia et Chun Fu Shao. « Pedestrian Evacuation Based on a Dynamic Parameters Model ». Applied Mechanics and Materials 97-98 (septembre 2011) : 956–59. http://dx.doi.org/10.4028/www.scientific.net/amm.97-98.956.
Texte intégralRésumé :
A dynamic parameters model is presented based on cellular automata for pedestrian evacuation in this paper. The dynamic parameters: Direction-parameter, Empty-parameter and Cognition-parameter are formulated to simplify tactically the decision-making process of pedestrians, which can reflect the pedestrian judgment on the surrounding conditions and decide the pedestrian’s choice of action. Pedestrian moving rules were established, according to two-dimensional cellular automaton. The simulation results of the model are analyzed. It is observed that there is a linear relationship between evacuation time and pedestrian density, however, there is a negative exponential relationship between evacuation time and exit width. The simulation results correspond with the actual, it is instructional significant for pedestrian evacuation.
3
Li, Sheng Nan, et Xin Gang Li. « A New Floor Field Model for Pedestrian Evacuation Considering Local Density ». Applied Mechanics and Materials 505-506 (janvier 2014) : 1172–78. http://dx.doi.org/10.4028/www.scientific.net/amm.505-506.1172.
Texte intégralRésumé :
The behavior of pedestrians around the corner of a room or a corridor is one of the most important features in pedestrian evacuating dynamics. In order to study this in detail, an existing potential field model is modified to capture the pedestrian dynamic around corner by introducing a local density parameter. The local density parameter of a cell is defined as the pedestrian occupancy of the surrounding eight neighbors. Simulations are carried out to study pedestrian evacuation in rooms with corners formed by internal obstacles and walls. The simulation results show that the new model can reproduce the empirical pedestrian dynamics around corner. Pedestrians prefer to walk to lower pedestrian density area although the route may be a little longer. It is also shown that the total evacuation time could be reduced for the evacuation corridor is fully utilized.
4
Zhu, Nuo. « Pedestrian Evacuation with a Improved Dynamic Parameters Model ». Applied Mechanics and Materials 505-506 (janvier 2014) : 1037–40. http://dx.doi.org/10.4028/www.scientific.net/amm.505-506.1037.
Texte intégralRésumé :
A improved dynamic parameters model is presented based on cellular automata in this paper.The dynamic parameters: Direction-parameter, Empty-parameter and Cognition-parameter are formulated to simplify tactically the decision-making process of pedestrians, which can reflect the pedestrian judgment on the surrounding conditions and decide the pedestrians choice of action. Simulation of pedestrian evacuation and pedestrian moving rules were established, according to two-dimensional cellular automaton Moore neighborhood. In the improved model, the impact of the pedestrian density around exits is considered, the simulation and experimental results prove that this improvement makes sense, because besides the spatial distance to exits, people may also choose the exit according to the pedestrian density around exits. And the simulation results of improved model is compared with experiment, comparison shows that the improved model can reproduce the experiment well. The improved model is useful for further study, it is instructional significant for pedestrian evacuation, avoiding or reducing the number injuries.
5
Qiao, Zhi, Lijun Zhao, Xinkai Jiang, Le Gu et Ruifeng Li. « A Navigation Probability Map in Pedestrian Dynamic Environment Based on Influencer Recognition Model ». Sensors 21, no 1 (22 décembre 2020) : 19. http://dx.doi.org/10.3390/s21010019.
Texte intégralRésumé :
One of the challenging problems in robot navigation is efficient and safe planning in a highly dynamic environment, where the robot is required to understand pedestrian patterns in the environment, such as train station. The rapid movement of pedestrians makes the robot more difficult to solve the collision problem. In this paper, we propose a navigation probability map to solve the pedestrians’ rapid movement problem based on the influencer recognition model (IRM). The influencer recognition model (IRM) is a data-driven model to infer a distribution over possible causes of pedestrian’s turning. With this model, we can obtain a navigation probability map by analyzing the changes in the effective pedestrian trajectory. Finally, we combined navigation probability map and artificial potential field (APF) method to propose a robot navigation method and verified it on our data-set, which is an unobstructed, overlooked pedestrians’ data-set collected by us.
6
Sana, Vladimír. « Dynamic Analysis of the Structure Exposed to the Moving Periodic Force and Viscoelastic Models of the Human Body ». Applied Mechanics and Materials 821 (janvier 2016) : 282–87. http://dx.doi.org/10.4028/www.scientific.net/amm.821.282.
Texte intégralRésumé :
Submitted paper is focused on dynamic analysis of the footbridge structure, which is represented by the simply supported beam. The continuous beam model was discretized by the FEM to MDOF system and loaded by pedestrians, walking across the structure. Three states of loading are considered in this paper. Firstly, it is the mathematical description of pedestrian's ordinary traffic, where each pedestrian is randomly generated by the Monte Carlo method. Secondly, the movement of single pedestrian, simplified by viscoelastic models, is introduced. Thirdly, the DLF model of stochastic vandals is investigated as well.
7
Hawryszków, Paweł, Roberto Pimentel, Rafaela Silva et Felipe Silva. « Vertical Vibrations of Footbridges Due to Group Loading : Effect of Pedestrian–Structure Interaction ». Applied Sciences 11, no 4 (3 février 2021) : 1355. http://dx.doi.org/10.3390/app11041355.
Texte intégralRésumé :
The vibration serviceability of footbridges has evolved from the adoption of a single pedestrian crossing in the resonance condition to load cases in which several pedestrians cross the structure simultaneously. However, in spite of this improvement, pedestrians continue to be considered as applied loads in codes of practice. Recent research has pointed out that modeling pedestrians as dynamic systems is a step further in the search for a more realistic design approach. This is explored in this paper, focusing on the case of vertical vibration. A two-span cable-stayed test structure was selected, and accelerations were measured from single and group crossings, both at the structure and at a pedestrian’s waist. Numerical simulations considering the pedestrians modeled as loads only and also as dynamic systems were implemented, and numerical and experimental time response vibration signatures were compared. Reductions of up to 25% and 20% in peak and RMS acceleration, respectively, were obtained when pedestrians were modeled as dynamic systems, in comparison with the less realistic model of pedestrians as loads only. Such reductions were shown to depend on the number of pedestrians involved in the group. The results, thus, highlight that pedestrian–structure interaction is an asset for the vibration serviceability design of footbridges.
8
CHAMNONGTHAI, K., et S. BOONRAT. « WALKING PEDESTRIAN TRACKING AMONG SEVERAL PEDESTRIANS BY DYNAMIC CAMERA ». International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems 13, no 02 (avril 2005) : 205–23. http://dx.doi.org/10.1142/s0218488505003400.
Texte intégralRésumé :
In tracking a walking pedestrian among multiple walking pedestrians by movable camera, the pedestrian-target determination is sometimes mistaken, and it needs real-time image processing. This paper proposes an approach for tracking a walking pedestrian among multiple walking pedestrians with dynamic camera mounted on a pan platform. The objective of this approach is to correctly select the target, and maintain target within field of view. The approach has three processes, consisting of motion extraction, target prediction and camera movement respectively. The motion extraction with background compensation is performed to determine the groups of moving edges. In the target prediction, target position is predicted by using appropriate size window to identify target among several target candidates and to increase the accuracy. The final calculated distance, and direction against target and error are cooperated to determine the predicted target position. At the final process, the camera is moved in order to locate the center of the view at the target center. The experiments were demonstrated by tracking a walking pedestrians at 1 m/s speed and five meters distance from camera. Each experiment roughly consumed 480 ms/frame processing time at 8.5 rev./s motor speed. The results showed that the system error was 5-8% for five walking patterns of a walking pedestrian situation. In the situation of multiple walking pedestrians, the demonstration were performed by tracking a pedestrian among two and three pedestrians, the results revealed that the system succeeded in maintaining the target within the field of view excepting the cases that the movement was suddenly changed in term of direction and speed.
9
Ge, Xinfang, Weirong Wang et Wei Yuan. « Research on dynamic characteristics of plate under pedestrian excitation based on Newmark-β ». Journal of Low Frequency Noise, Vibration and Active Control 37, no 4 (21 février 2018) : 682–99. http://dx.doi.org/10.1177/1461348418756025.
Texte intégralRésumé :
Development of micro and ultra-precision machining, precision instruments and equipment, precision assembly and testing has put forward more and more high requirements to vibration isolation on environmental elements, especially the pedestrian excitation generated by workers' normal walking. Therefore, it is very important to study the pedestrian excitation's influence on vibration characteristics of precision instruments and equipment. In this study, dynamic model including mathematical model of pedestrian excitation, interaction model between pedestrian and rectangular plate structure, the human–plate coupled dynamic equation in vertical direction of pedestrian–plate structure was established. And then we use the Newmark-β method to solve the time-domain step-by-step integration of the first four order modes' dynamic equations and study the influence of the linear notion trajectory along the central axis direction on the dynamic characteristics of the rectangular plate. By simulation, we discussed plate structure response under different conditions, including plate structure displacement and acceleration response under the single person excitation with different velocities, under normal walking velocity with different number of pedestrians and under this case of different distance between two pedestrians. The results show that the structural vibration induced by pedestrian excitation has great influence on dynamic characteristics of plate.
10
Liu, Gang, Jing He, Zhiyong Luo, Wunian Yang et Xiping Zhang. « Dynamic analysis of pedestrian crossing behaviors on traffic flow at unsignalized mid-block crosswalks ». International Journal of Modern Physics B 29, no 15 (25 mai 2015) : 1550100. http://dx.doi.org/10.1142/s0217979215501003.
Texte intégralRésumé :
It is important to study the effects of pedestrian crossing behaviors on traffic flow for solving the urban traffic jam problem. Based on the Nagel–Schreckenberg (NaSch) traffic cellular automata (TCA) model, a new one-dimensional TCA model is proposed considering the uncertainty conflict behaviors between pedestrians and vehicles at unsignalized mid-block crosswalks and defining the parallel updating rules of motion states of pedestrians and vehicles. The traffic flow is simulated for different vehicle densities and behavior trigger probabilities. The fundamental diagrams show that no matter what the values of vehicle braking probability, pedestrian acceleration crossing probability, pedestrian backing probability and pedestrian generation probability, the system flow shows the "increasing–saturating–decreasing" trend with the increase of vehicle density; when the vehicle braking probability is lower, it is easy to cause an emergency brake of vehicle and result in great fluctuation of saturated flow; the saturated flow decreases slightly with the increase of the pedestrian acceleration crossing probability; when the pedestrian backing probability lies between 0.4 and 0.6, the saturated flow is unstable, which shows the hesitant behavior of pedestrians when making the decision of backing; the maximum flow is sensitive to the pedestrian generation probability and rapidly decreases with increasing the pedestrian generation probability, the maximum flow is approximately equal to zero when the probability is more than 0.5. The simulations prove that the influence of frequent crossing behavior upon vehicle flow is immense; the vehicle flow decreases and gets into serious congestion state rapidly with the increase of the pedestrian generation probability.
11
Jin, Lianghai, Mei Fang, Shu Chen, Wenfan Lei et Yun Chen. « Tangential Change Behavior and Pedestrian Simulation of Multichannel Evacuation Crowd ». Mathematical Problems in Engineering 2020 (21 octobre 2020) : 1–13. http://dx.doi.org/10.1155/2020/7649094.
Texte intégralRésumé :
In evacuation, the velocity difference of adjacent pedestrians before and after often leads to tangential change of pedestrian location in channel. This tangential change behavior and its interaction disturb the stable state of crowd evacuation in multiple channels, which can affect the efficiency of crowd evacuation and even cause trampling accidents. This paper considers the dynamic comfort distance and the expected speed and analyzes the relative position changes after pedestrians change lanes. It investigates the conditions of tangential change behavior and defines the rules of tangential change behavior processing. Meanwhile, it investigates the crowd’s tangential change behavior and its interaction process, revealing the crowd evacuation mechanism of tangential change behavior conditions. Simulation results show that as the crowd density gradually increases, pedestrians exhibit the evolutionary characteristic of “no tangential change ⟶ occasional tangential change ⟶ frequent tangential change ⟶ closely following.” The evacuation speed is obviously influenced by pedestrian’s tangential change behavior and crowd density; when the pedestrian density ρ = 2.0 and ρ = 3.0 , the tangential change behavior not only makes the speed difference and fluctuation between different lanes great but also has the same effect on the average speed of pedestrians. The results of this study can provide theoretical insights into the organization of multichannel evacuation and expand the theoretical space of crowd dynamics in an evacuation.
12
Guo, Yongqing, Siyuan Ma, Fulu Wei, Liqun Lu, Feng Sun et Jie Wang. « Analysis of Behavior Characteristics for Pedestrian Twice-Crossing at Signalized Intersections Based on an Improved Social Force Model ». Sustainability 14, no 4 (10 février 2022) : 2003. http://dx.doi.org/10.3390/su14042003.
Texte intégralRésumé :
At urban signalized intersections, pedestrian twice-crossing is usually viewed as a complex human behavior, since there are many factors influencing it. Mostly, pedestrians engage in a complicated cognitive process of perception, attention and decision-making. Therefore, it is necessary to identify the major factors affecting this behavior, and develop an effective pedestrian dynamic model, in order to increase the safety and efficiency of crossing streets. This study proposes a force-based model of pedestrian dynamics by improving the classic social force model, in order to determine the influencing factors and quantify the forces acting on pedestrians crossing in two stages at signalized intersections. Through analyzing the characteristics of pedestrian twice-crossing behavior, the social force model was enhanced by providing a new component of the green signal countdown. The improved model includes four parts of the self-driving force in the ideal state, the repulsive and attractive forces generated by surrounding pedestrians, the resistance of the crosswalk boundary line, and the force produced by the green signal countdown. Each part was considered with qualitative analysis and quantitative calculation. The results show that the proposed model can achieve high accuracy in measuring the forces acting on pedestrian twice-crossing. The findings of this study have great implications for designing pedestrian facilities and optimizing pedestrian signal timings, helping thus to increase the mobility and safety of pedestrian twice-crossing.
13
Chen, Zhou, Siyuan Chen, Xijun Ye et Yunlai Zhou. « A Study on a Mechanism of Lateral Pedestrian-Footbridge Interaction ». Applied Sciences 9, no 23 (3 décembre 2019) : 5257. http://dx.doi.org/10.3390/app9235257.
Texte intégralRésumé :
Based on the pedestrian lateral force hybrid Van der Pol/Rayleigh model, this study investigates the interaction dynamic model of a pedestrian-flexible footbridge lateral coupling system. A multi scale method is adopted to decouple the equation. The paper also studies the nonlinear dynamic response of the pedestrian-footbridge coupling system as well as the relationship between the lateral displacement of pedestrians and flexible footbridges, and the lateral interaction of the two variables. The results show that with the same frequency tuning parameters, when the mass ratio of pedestrians and footbridges is very small, the larger the mass ratio is, the larger the lateral response amplitude of pedestrians becomes. Conversely, when the mass ratio of pedestrians and footbridges is much larger, the larger the mass ratio is, the smaller the response amplitude becomes. When the natural frequency of a footbridge is larger, its Phase Angle becomes larger. As the lateral amplitude of pedestrians increases, the Phase Angle approaches zero. Moreover, regarding the variation of the Phase Angle between the interaction force and footbridge lateral vibration speed based on the lateral relative displacement of pedestrians, of which the variation range is (0, π ), as the pedestrians’ lateral amplitude increases, the Phase Angle approaches − π / 2 . The dynamic load coefficient varies linearly with the lateral amplitude of pedestrian vibrations.
14
Jiang, Xue Ling, Chao Yun Long, Shui Jie Qin, Li Ping Wang et Jiang Hui Dong. « Pedestrian Evacuation Simulation Based on Dynamic Parameter Model with Friction ». Applied Mechanics and Materials 543-547 (mars 2014) : 1876–79. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.1876.
Texte intégralRésumé :
An expanded dynamic parameter model is introduced based on cellular automata. In this model friction is modeled quantitatively. The dynamic parameters including direction parameter and empty parameter are formulated to simplify tactically the process of making decisions for pedestrian evacuation. The pedestrian moving rule is modified by bringing in the conception of friction under high density, corresponding simulations of pedestrian evacuation is carried out. The improved model considers the impact of interactions among pedestrians on the evacuation process. Therefore, it is more accordance with actual circumstance than the original dynamic parameters model.
15
Li, Mao Qi. « Study on Dynamic Test of a Large Span Steel Truss Pedestrian Bridge ». Advanced Materials Research 255-260 (mai 2011) : 769–75. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.769.
Texte intégralRésumé :
To prevent a long-span steel truss pedestrian bridge vibration problem, finite element model was established by analysis software ANSYS, studies on this pedestrian bridge’s vibration question were carried on by frequent spectrum analysis based on recorded data and modal analysis. It has determined the vibrating level. In addition, the reason for this pedestrian bridge’s vibration has been thoroughly analyzed from the pedestrian and traffic, and had dynamic response analysis of pedestrian bridges under the crowd of pedestrians walking load. Then the main reason which causes the actual vibration characteristic has been found. Thus these both gave the reasonable explanation to the vertical vibration and provided the reference for the similar structure’s dynamic performance research.
16
Zheng, Xia Zhong, Dan Tian, Ming Zhang, Chaoran Hu et Liyang Tong. « A Stairs Evacuation Model Considering the Pedestrian Merging Flows ». Discrete Dynamics in Nature and Society 2019 (10 décembre 2019) : 1–11. http://dx.doi.org/10.1155/2019/7615479.
Texte intégralRésumé :
Pedestrian merging flows are common in a stairs evacuation process, which involves complex interactions among pedestrians that substantially restrict the efficiency of the stairs evacuation process. Analyzing the pedestrian merging flows process and improving the efficiency of stairs evacuation are urgent and essential tasks. A novel simplified stairs evacuation model for simulating and analyzing the stairs evacuation process, which considers the impact of merging flows, is proposed in this process. The dynamic pedestrian output rate of a floor platform is calculated by the number of pedestrians on the floor platform. The merging ratio determined by the design size of stairs is adopted to determine the ratio between the stairs pedestrian flow and the floor pedestrian flow in the pedestrian output rate of the floor platform. To evaluate the stairs evacuation process is divided into three stages based on the pedestrian merging flows process, and the evacuation time at each stage is computed by the dynamic pedestrian output rate of the floor platform. The stairs evacuation capacity is calculated by the evacuation time and the number of pedestrians. A case study of a six-floor building evacuation is investigated, and the reliability and feasibility of the proposed model is verified. By establishing different merging ratios, the optimal merging ratio is obtained by comparing the evacuation capacities of different merging ratios, which provides a reference of stairs design for designers.
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Zhou, Shi, Wei Feng Su, Jun Li Guo et Qian Hui Pu. « Analysis on Natural Vibration and Dynamic Response of Footbridge ». Applied Mechanics and Materials 361-363 (août 2013) : 1389–96. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.1389.
Texte intégralRésumé :
According to vibration problem of the footbridge, the dynamic characteristics and dynamic responses of the footbridge were analyzed under pedestrian load. Based on one 22m×10 straight line footbridge, this paper established the spatial finite element model to analyze its natural vibration characteristics and discuss the effects on the natural vibration characteristics induced by both connection factors of beam ends and pedestrians weight. And then the dynamic responses of the footbridge caused by pedestrian dynamic load were calculated to analyze the structure stress. In addition, to analyze the calculation result of displacement responses so as to evaluate the comfort of pedestrians. The results show that the natural frequency is lower, and it will probably induce the resonance and larger dynamic response value under pedestrian load although the footbridge structure is safe. Moreover, reducing vibration methods and treatment measures to the footbridge were introduced, and the effective measure was suggested to reduce vibration amplitude at last.
18
Hoogendoorn, Serge, et Piet H. L. Bovy. « Gas-Kinetic Modeling and Simulation of Pedestrian Flows ». Transportation Research Record : Journal of the Transportation Research Board 1710, no 1 (janvier 2000) : 28–36. http://dx.doi.org/10.3141/1710-04.
Texte intégralRésumé :
Insight into pedestrian flow operations is important in both planning and geometric design of infrastructure facilities such as railway stations as well as in the management of pedestrian flows in such facilities. Lack of empirical knowledge regarding the characteristics of pedestrian flows under varying circumstances and designs motivates using a model-based approach. In this study, a new pedestrian flow model based on the gaskinetic modeling paradigm is established. The mesoscopic equations describe the dynamics of so-called pedestrian phase-space density, which can be considered as a two-dimensional generalization of the phase-space density used in gas-kinetic vehicular traffic flow. Convection, acceleration, and noncontinuum transition terms govern the dynamics. The latter terms reflect the dynamic influence of pedestrians decelerating and the changing angle of movement due to pedestrians interacting. Numerical solutions of the resulting gas-kinetic equations are established by using a novel particle discretization approach. Essentially, this approach upgrades the mesoscopic equations to a microscopic pedestrian flow simulation model. Using the particle discretization approach, the model’s behavior is tested for different test-case scenarios. The model is shown to produce plausible speed-density functions from which walking speeds and travel times can be derived for a variety of conditions.
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Liang, Huiqi, Zhiqiang Zhang et Peizi Wei. « Theoretical Derivation and Parameters Analysis of a Human-Structure Interaction System with the Bipedal Walking Model ». Journal of Mathematics 2021 (2 mars 2021) : 1–28. http://dx.doi.org/10.1155/2021/6683083.
Texte intégralRésumé :
The excessive vertical vibration of structures induced by walking pedestrians has attracted considerable attention in the past decades. The bipedal walking models proposed previously, however, merely focus on the effects generated by legs and ignore the effects of the dynamics of body parts on pedestrian-structure interactions. The contribution of this paper is proposing a novel pedestrian-structure interaction system by introducing the concept of the continuum and a different variable stiffness strategy. The dynamic model of pedestrian-structure coupling system is established using the Lagrange method. The classical mode superposition method is utilized to calculate the response of the structure. The state-space method is employed to determine natural frequencies and damping ratio of the coupled system. Based on the proposed model, numerical simulations and parametric analysis are conducted. Numerical simulations have shown that the continuum enables the pedestrian-structure system to achieve the stable state more efficiently than the classic model does, which idealizes the body as a concentrated or lumped mass. The parametric study reveals that the presence of pedestrians is proved to significantly decrease the frequency of human-structure interaction system and improve its damping ratio. Moreover, the parameters of the bipedal model have a noticeable influence on the dynamic properties and response of the pedestrian-structure system. The bipedal walking model proposed in this paper depicts a pattern of pedestrian-structure interactions with different parameter settings and has a great potential for a wide range of practical applications.
20
Zhu, Wenjie, Rongyong Zhao, Hao Zhang, Ping Jia, Yan Wang, Cuiling Li et Yunlong Ma. « Crowd Stability Analysis Based on Pedestrian Abnormal Postures ». Journal of Physics : Conference Series 2224, no 1 (1 avril 2022) : 012062. http://dx.doi.org/10.1088/1742-6596/2224/1/012062.
Texte intégralRésumé :
Abstract Abnormal behaviors of pedestrians in crowd gathering public places are important factors affecting the stability of crowd flow. Pedestrian abnormal postures are important manifestation of abnormal behaviors, which often leads to local turbulence, disturbance and density-speed fluctuations. It is urgent to discover the disturbance mechanism of abnormal pedestrian posture on the stability of crowd flow. This study intends to establish machine vision, kinematics, dynamic models and crowd confluence dynamic models for typical abnormal pedestrian postures in public places. We mainly use computer vision related technology based to recognize abnormal postures of pedestrians in videos, constructs a network matrix of key posture nodes, and studys the kinematics characteristics of abnormal posture nodes. Considering the number of pedestrians and the characteristics of the architectural scenes, we design a workflow to select the appropriate macro or micro dynamic model to build the crowd flow model. To validate the propuesd model, case in Shanghai Hongqiao railway station is studied.
21
Li, Yongxing, Wenjing Wu, Xin Guo, Yu Lin et Shiguang Wang. « Effect of group behavior on pedestrian choice for vertical walking facilities ». International Journal of Modern Physics B 34, no 07 (17 mars 2020) : 2050056. http://dx.doi.org/10.1142/s0217979220500563.
Texte intégralRésumé :
Analyzing the characteristics of group behavior, leader-follower model which adopts dynamic group floor field to represent the attraction in a group is used to model pedestrian group behavior. Pedestrian choice model of vertical walking facilities based on support vector machine (SVM) with the effect of group behavior is established. Fusing pedestrian choice model of vertical walking facilities and leader-follower model into a cellular automata (CA)-based pedestrian simulation model, we simulate the pedestrian choice process for vertical walking facilities with the effect of group behavior. The simulation results indicate that with the effect of group behavior, the choice results of some pedestrians are changed, and the efficiency of pedestrians passing is reduced. To some extent, the efficiency of pedestrians passing is improved with the mean distribution of luggage in each group.
22
Gao, Yan-An, Qing-Shan Yang, Yun Dong, Chao Chen et Tao-Ping Ye. « Dynamic Behavior of Slab Induced by Pedestrian Traffic ». International Journal of Structural Stability and Dynamics 19, no 12 (décembre 2019) : 1950154. http://dx.doi.org/10.1142/s0219455419501542.
Texte intégralRésumé :
This study comprehensively explores the dynamic behavior of a slender slab due to the excitation of pedestrian traffic. Three kinds of excitation models are adopted to describe the vibration of the slab induced by pedestrians. A comparison of the structural responses shows that the bipedal model results in larger vibrations than the mass–spring–damper or pseudo-excitation models. Further research indicates that the pedestrians evidently alter the dynamic properties of the slab by affecting its frequency and damping capacity. The slab tends to be more flexible at a lower frequency as the pedestrian walks across its surface while its damping capacity is improved. In contrast, the slab can increase the frequency, while decreasing the damping of the pedestrian model. Thus, the slab also alters the properties of the pedestrians. In addition, an investigation of the bipedal model parameters indicates that the variations of the leg stiffness, damping, and body mass have distinct effects on the slab characteristics and vibrations. In order to assess the response of the slab to a crowd, a new simplified theory is introduced to describe the dynamic properties of the slab under multi-layout excitations, including human influences resulting from different body properties. The results of this study provide potential ways for understanding the vibratory mechanisms of slender structures such as footbridges, grandstands, or stations under crowd excitations.
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Sighencea, Bogdan Ilie, Ion Rareș Stanciu et Cătălin Daniel Căleanu. « D-STGCN : Dynamic Pedestrian Trajectory Prediction Using Spatio-Temporal Graph Convolutional Networks ». Electronics 12, no 3 (26 janvier 2023) : 611. http://dx.doi.org/10.3390/electronics12030611.
Texte intégralRésumé :
Predicting pedestrian trajectories in urban scenarios is a challenging task that has a wide range of applications, from video surveillance to autonomous driving. The task is difficult since pedestrian behavior is affected by both their individual path’s history, their interactions with others, and with the environment. For predicting pedestrian trajectories, an attention-based interaction-aware spatio-temporal graph neural network is introduced. This paper introduces an approach based on two components: a spatial graph neural network (SGNN) for interaction-modeling and a temporal graph neural network (TGNN) for motion feature extraction. The SGNN uses an attention method to periodically collect spatial interactions between all pedestrians. The TGNN employs an attention method as well, this time to collect each pedestrian’s temporal motion pattern. Finally, in the graph’s temporal dimension characteristics, a time-extrapolator convolutional neural network (CNN) is employed to predict the trajectories. Using a lower variable size (data and model) and a better accuracy, the proposed method is compact, efficient, and better than the one represented by the social-STGCNN. Moreover, using three video surveillance datasets (ETH, UCY, and SDD), D-STGCN achieves better experimental results considering the average displacement error (ADE) and final displacement error (FDE) metrics, in addition to predicting more social trajectories.
24
Liang, Huiqi, Wenbo Xie, Peizi Wei, Dehao Ai et Zhiqiang Zhang. « Identification of Dynamic Parameters of Pedestrian Walking Model Based on a Coupled Pedestrian–Structure System ». Applied Sciences 11, no 14 (12 juillet 2021) : 6407. http://dx.doi.org/10.3390/app11146407.
Texte intégralRésumé :
As human occupancy has an enormous effect on the dynamics of light, flexible, large-span, low-damping structures, which are sensitive to human-induced vibrations, it is essential to investigate the effects of pedestrian–structure interaction. The single-degree-of-freedom (SDOF) mass–spring–damping (MSD) model, the simplest dynamical model that considers how pedestrian mass, stiffness and damping impact the dynamic properties of structures, is widely used in civil engineering. With field testing methods and the SDOF MSD model, this study obtained pedestrian dynamics parameters from measured data of the properties of both empty structures and structures with pedestrian occupancy. The parameters identification procedure involved individuals at four walking frequencies. Body frequency is positively correlated to the walking frequency, while a negative correlation is observed between the body damping ratio and the walking frequency. The test results further show a negative correlation between the pedestrian’s frequency and his/her weight, but no significant correlation exists between one’s damping ratio and weight. The findings provide a reference for structural vibration serviceability assessments that would consider pedestrian–structure interaction effects.
25
Kłusek, Adrian, Paweł Topa, Jarosław Wąs et Robert Lubaś. « An implementation of the Social Distances Model using multi-GPU systems ». International Journal of High Performance Computing Applications 32, no 4 (4 décembre 2016) : 482–95. http://dx.doi.org/10.1177/1094342016679492.
Texte intégralRésumé :
We propose a new approach for using GPUs in large scale simulations of pedestrian evacuation. The Social Distances Model is designed for efficient modeling of pedestrian dynamics. This cellular automata based model, when implemented on the most modern GPUs, can simulate up to 106–108 entities. However, a valuable simulation of pedestrian evacuation must include various factors that govern pedestrian movement, for example, information provided by event organizers and navigation or allocation of other pedestrians. The most common method for introducing such information into simulations is the application of different floor fields. The floor fields provide “local knowledge” that affects pedestrians by modifying the transition functions of an applied cellular automaton. The main disadvantage of this method is its time consuming updating process. We propose a GPU based calculation of static and dynamic floor fields, whereby simulations that use several different floor fields can be efficiently calculated. A single GPU is able to cope with the Social Distance Model calculations, while other GPUs update dynamic floor fields constantly or when required. We also present the classic approach to performing cellular automata based simulations on systems with multiple processing units. The lattice is simply partitioned between the available GPUs. We compare these two approaches in terms of performance and functionality.
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Kim, Jeongyun, Sehyun Tak, Michel Bierlaire et Hwasoo Yeo. « Trajectory Data Analysis on the Spatial and Temporal Influence of Pedestrian Flow on Path Planning Decision ». Sustainability 12, no 24 (13 décembre 2020) : 10419. http://dx.doi.org/10.3390/su122410419.
Texte intégralRésumé :
The modeling of walking behavior and design of walk-friendly urban pathways have been of interest to many researchers over the past decades. One of the major issues in pedestrian modeling is path planning decision-making in a dynamic walking environment with different pedestrian flows. While previous studies have agreed that pedestrian flow influences path planning, only a few studies have dealt with the empirical data to show the relationship between pedestrian flow and path planning behavior. This study introduces a new methodology for analyzing pedestrian trajectory data to find the dynamic walking conditions that influence the path planning decision. The comparison of the pedestrians’ path shows that the higher proportion of opposite flows are, the greater they influence the path selection decision. In this study, we investigate the relationship between the opposite flow changes and path planning behavior and find the spatial and temporal ranges of the opposite flow that affects the path planning behavior. Lastly, we find the ratio of pedestrians that update their paths with respect to the opposite flow rate.
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XU, SHA, XIANLONG JIN, CHUANG QIN et XIANGHAI CHAI. « PERSONALIZED CUSTOMIZATION METHOD OF HYBRID HUMAN MODEL FOR PEDESTRIAN-VEHICLE ACCIDENT RECONSTRUCTION ». Journal of Mechanics in Medicine and Biology 21, no 02 (16 février 2021) : 2150009. http://dx.doi.org/10.1142/s0219519421500093.
Texte intégralRésumé :
Traffic accident reconstruction is a reverse dynamic problem, which requires hundreds of iterations to reconstruct the whole process of accident. However, in current pedestrian-vehicle accident reconstructions, it is difficult to quickly establish a pedestrian model based on specific cases, and it is hard to solve the contradiction between calculation accuracy and calculation time. In this paper, a personalized pedestrian customization method is proposed. First, the pedestrian structure is divided into independent modules according to obvious bony markers. For each independent module, multi-body (MB) model and finite element (FE) model are established, respectively. Then the appropriate modules are selected to form the whole hybrid pedestrian model. This method can customize the structure of pedestrian model according to the injury characteristics of pedestrians in specific accidents, and customize the parameters of pedestrian model according to the height and weight of pedestrians. The impact simulation tests are carried out on hybrid pedestrian models to verify the reliability of the models. The proposed method can effectively improve the modeling efficiency of pedestrian models and the reconstruction quality of pedestrian traffic accidents.
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Gasparini, Francesca, Marta Giltri et Stefania Bandini. « Safety perception and pedestrian dynamics : Experimental results towards affective agents modeling ». AI Communications 34, no 1 (15 février 2021) : 5–19. http://dx.doi.org/10.3233/aic-201576.
Texte intégralRésumé :
The modeling of a new generation of agent-based simulation systems supporting pedestrian and crowd management taking into account affective states represents a new research frontier. Pedestrian behaviour involves human perception processes, based on subjective and psychological aspects. Following the concept of pedestrian environmental awareness, each walker adapts his/her crossing behaviour according to environmental conditions and his/her perception of safety. Different pedestrian behaviours can be related to subjective mobility and readiness to respond, and these factors are strongly dependent on the subjective interaction with the environment. Having additional inputs about pedestrian behaviour related to their perception processes could be useful in order to develop a more representative pedestrian dynamic model. In particular, the subjective perception of the safeness of crossing should be taken into consideration. In order to focus on the pedestrians’ perception of safe road crossing and walking, an experiment in an uncontrolled urban scenario has been carried out. Besides more conventional self-assessment questionnaires, physiological responses have been considered to evaluate the affective state of pedestrians during the interaction with the urban environment. Results from the analysis of the collected data show that physiological responses are reliable indicators of safety perception while road crossing and interacting with real urban environment, suggesting the design of agent-based models for pedestrian dynamics simulations taking in account the representation of affective states.
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Zhang, Hui-ling, Yuan-qiang Chen et Xian-xian Pang. « A Study on the Conversion Method Based on Standard Pedestrian Equivalent Factors at Signalized Crosswalks in China ». International Journal of Intelligent Transportation Systems Research 20, no 1 (17 février 2022) : 320–29. http://dx.doi.org/10.1007/s13177-022-00296-3.
Texte intégralRésumé :
AbstractIn order to more accurately assess the pedestrian level of service (PLOS) of crosswalks and to more rationally design the pedestrian signal timing, a method of calculating the standard pedestrian equivalent (SPE) factors at the signalized crosswalk in China was proposed in this study by considering the differences in static and dynamic characteristics amongst pedestrians. Firstly, the pedestrians were classified into five types using the pedestrian field data collected at the 3 signalized crosswalks in Chongqing, China. Then, by considering the parameters selection of the pedestrian LOS at signalized crosswalks, the SPE method based on pedestrian delays was derived, and the calculation models of pedestrian delays were presented for different pedestrian arrival patterns. A case analysis was conducted using the methods proposed in this paper, and the results show that the SPE values for minors, young and middle-aged females, elderly males and elderly females were 1.213, 1.067, 1.229 and 1.348, respectively. In addition, the results of the in-situ application to the pedestrian signal timing at the signalized crosswalk were achieved. This research can provide reference for practice related to transportation fields such as pedestrian capacity analysis and pedestrian signal timing design.
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Xiao, Qian, et Jiayang Li. « Pedestrian Evacuation Model considering Dynamic Emotional Update in Direction Perception Domain ». Complexity 2021 (1 septembre 2021) : 1–16. http://dx.doi.org/10.1155/2021/5530144.
Texte intégralRésumé :
Traditional dynamic models cannot fully describe the microdetails of the impact of emotional contagion on individual state and behavior when pedestrian evacuation is simulated. This paper addresses the problem by constructing a dynamic evolution mechanism among emotion, state, and behavior. First, the direction perception domain of pedestrians during evacuation is defined. Then, the dynamic emotional perception of pedestrians during an evacuation is studied, considering the emotional increment caused by personal walking speed and others in the direction perception domain. Next, emotional contagion is introduced into the improved cellular automata (CA) simulation model in the floor field (FF), entitled the “CECA model.” The transfer probability of pedestrians in different states is proposed by defining “susceptible emotional state” and “infectious emotional state.” Finally, the simulation results are compared with known models. The results demonstrate that the improved model can improve the evacuation efficiency of the system significantly. Simultaneously, the effects of emotional threshold, infection coefficient, calm coefficient, and perception radius of the evacuation system on the pedestrian evacuation process are simulated and analyzed, providing a basis for evacuation managers to formulate evacuation strategies.
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Lian, Haitao, Yike Hu et R. D. Rohmat Saedudin. « Evacuation simulation of different flow ratios in low-density state ». Open Physics 17, no 1 (5 avril 2019) : 77–85. http://dx.doi.org/10.1515/phys-2019-0009.
Texte intégralRésumé :
Abstract The relationship between the factors of formation mechanism of stratification and the pedestrian ratio in low-density state has not been analyzed by the existing human flow evacuation simulation method, so that the simulation effect is poor. Thus, the evacuation simulation method for different flow ratios in low-density state is proposed to analyze the walking characteristics of the opposite pedestrians. On the basis of the random deviation grid gas model, the view field of pedestrian is introduced as one parameter. Considering the preference characteristics of pedestrians for the movement of open areas within the view field, the improved random deviation grid gas model is constructed. Through the model, the stratification characteristics of the opposite pedestrian flow in the simple channel scene are simulated. The results show that the proposed method can reproduce the characteristics of non-layering phenomenon of opposite pedestrian flow in low-density state. According to the probability of layer formation, the density of the opposite pedestrian flow is divided into five intervals. The opposite pedestrian flow in the critical density region is metastable, and is susceptible to interference. These results are consistent with the dynamic evolution of the actual opposite pedestrian flow.
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Yang, Zheng, Buyu Jia, Quansheng Yan, Xiaolin Yu et Yinghao Zhao. « Nonlinear Stochastic Analysis of Footbridge Lateral Vibration Based on Probability Density Evolution Method ». Shock and Vibration 2019 (27 octobre 2019) : 1–16. http://dx.doi.org/10.1155/2019/2606395.
Texte intégralRésumé :
Footbridge lateral vibration remains an unsolved problem and is characterized by the following: (1) pedestrians are sensitive to bridge vibration, which causes the pedestrian’s excitation being dependent on the bridge vibration; (2) pedestrian lateral excitation is a stochastic process rather than a perfect periodic load. Therefore, footbridge lateral vibration is essentially a complex nonlinear stochastic vibration system. Thus far, an effective method of dealing with such nonlinear stochastic vibration of footbridges remains lacking. A framework based on the probability density evolution (PDE) method is presented. For the mathematical model, the parameter resonance model is used to describe the pedestrian-bridge interaction while treating the pedestrian lateral excitation as a narrow-band process. For the analysis method, PDE is used to solve the nonlinear stochastic equations in combination with the number theoretical and finite difference methods. The proposed method establishes a new approach in studying footbridge lateral vibration. First, PDE based on the small sample strategy avoids the large amount of computation. Second, the randomness of both structural parameters and pedestrian lateral excitation could be taken into consideration by the proposed method. Third, based on the probability results with rich information, the serviceability, dynamic reliability, and random stability analyses are realized in a convenient manner.
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Sun, Xu, Kun Lin, Yu Wang, Shuo Ma et Huapu Lu. « A Study on Pedestrian–Vehicle Conflict at Unsignalized Crosswalks Based on Game Theory ». Sustainability 14, no 13 (23 juin 2022) : 7652. http://dx.doi.org/10.3390/su14137652.
Texte intégralRésumé :
A dynamic game model based on multiple decision makers is developed to minimize pedestrian–vehicle conflicts at unsignalized crosswalks. The characteristics of pedestrians and drivers crossing the street are divided into traffic features, behavioral characteristics, and psychological factors, using data collected from a survey of pedestrian crossing behavior. Based on waiting delay and risk assessment, a utility model of pedestrian crossing choice behavior is presented, and a probability model for different phases of the waiting stage is developed by splitting the waiting process into three stages with pedestrian waiting duration. The payment function and the game model of pedestrian–vehicle conflict based on distinct previous decision makers are developed using game theory and “mixed strategy”, and they are resolved in equilibrium.
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Kumar, Prakash, Anil Kumar et Vitomir Racic. « Modeling of Longitudinal Human Walking Force Using Self-Sustained Oscillator ». International Journal of Structural Stability and Dynamics 18, no 06 (juin 2018) : 1850080. http://dx.doi.org/10.1142/s0219455418500803.
Texte intégralRésumé :
The paper proposes a self-sustained single-degree-of-freedom oscillator to accurately generate the longitudinal contact force between a pedestrian’s feet and the supporting flat rigid surface. The model is motivated from the self-sustained nature of pedestrian walking, i.e. a pedestrian produces the required internal energy to maintain a repetitive body motion. It is derived by adding two nonlinear terms to the conventional Rayleigh oscillator to yield odd as well as even harmonics, as observed in experimentally recorded longitudinal force data. For the dynamic analysis of the oscillator, two methods are adopted: the energy balance method and the Lindstedt–Poincare perturbation technique. Moreover, the least-squares identification procedure is used to identify values of the oscillator parameters from the force records of 12 different pedestrians walking on an instrumented treadmill at 10 walking speeds. The results generated by the proposed oscillator agree well with the experimental data.
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Gao, Yan-An, Qing-Shan Yang et Jing-Wei Qin. « Bipedal Crowd–Structure Interaction Including Social Force Effects ». International Journal of Structural Stability and Dynamics 17, no 07 (septembre 2017) : 1750079. http://dx.doi.org/10.1142/s0219455417500791.
Texte intégralRésumé :
This paper proposes a vertical crowd-structure interaction (CSI) model, considering the social force interaction effect among pedestrians. Pedestrian, as the basic unit of crowd, is modeled by a dynamic bipedal system with one lump mass and two compliance legs. The CSI model can be applied to self-determining the walking velocities of pedestrians instead of the sensitive passive control force for a stable gait from the original human–structure interaction (HSI) model. The damping compliance legs are responsible for the energy transfer between the pedestrian and the supporting structures during the dynamic walking process. Numerical studies with several pedestrians walking on a simply supported beam show an improvement of the damping property of the structure, but a decrease of the deterioration of natural frequency of the structure. The experiences gained in this study can be adopted for further study on the more complicated social force interaction among pedestrians in a large crowd passing some slender structures such as large-span footbridge.
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Eremeev, Valery, Gennady Shmelev, Pavel Eremeev et Daniil Eremeev. « Trends in the development of composite reinforced concrete structures of pedestrian aboveground overpasses ». E3S Web of Conferences 274 (2021) : 02006. http://dx.doi.org/10.1051/e3sconf/202127402006.
Texte intégralRésumé :
Pedestrian bridges are an important part of the urban infrastructure that ensures the safety and comfort of pedestrians. They have a number of distinctive features compared to road bridges. Also, the pedestrian load itself has a significant dynamic component, which can lead to the occurrence of resonant phenomena. Composite reinforced concrete bridges are widely used among the road bridges. This is due to the possibility of including the roadway structure in the act, which increases the load-bearing capacity and reliability of the structure. The same advantages are typical for pedestrian aboveground overpasses. However, pedestrian bridges have a number of features that affect the operation of the composite reinforced concrete structure. It is well-known that the difference between bending structures in civil construction and bending structures in bridge and road construction is the ratio of the rigidness of the concrete and steel parts. The load on pedestrian aboveground overpasses is similar to the temporary load in civil buildings, adjusted for a large dynamic component. But at the same time, the spans of pedestrian aboveground overpasses are similar to the spans of road bridges. In this article, the prospects for the development of composite reinforced concrete structures of pedestrian overpasses are reviewed.
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Oleksakova, Ivana, et Marek Magát. « Influence of the Wind in Passages ». Applied Mechanics and Materials 820 (janvier 2016) : 365–70. http://dx.doi.org/10.4028/www.scientific.net/amm.820.365.
Texte intégralRésumé :
This paper is concerned with wind influence on pedestrians in different buildings underpasses where with using of Computational Fluid Dynamic (CFD) is made study about proportion of buildings and underpasses affecting velocity and so pedestrian comfort in passage. For simulation of wind flow is used OpenFOAM software with k-epsilon model, which is in many papers represents as one of the best and most reasonable model for evaluation pedestrian comfort.
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LENG, BIAO, JIANYUAN WANG, XIAOXI ZHAO, JUN FANG et ZHANG XIONG. « OUT FLOW IN A VIRTUAL MTR STATION USING A LOCAL VIEW FLOOR FIELD MODEL ». International Journal of Modern Physics C 24, no 06 (mai 2013) : 1350037. http://dx.doi.org/10.1142/s012918311350037x.
Texte intégralRésumé :
The floor field (FF) model, up until now, has been the most widely used simulation in pedestrian flow dynamics for simple based scenarios. This paper presents an improvement on and upon the local view FF model by simulating pedestrian flow in more complex scenarios with typical goals and obstacles that may block or assist the sight of the pedestrian. In addition this model will also provide a detailed analysis entailing the simulation of multi-goal selections. This involves the visibility information on each cell being set, and a dynamic priority list of goals for every pedestrian being updated as he/she moves. The pedestrians select the convenient goal according to the priority of goals, the distances to the candidate goals and the degree of congestion. To aid in the theory of this and to make a better understanding of reality, a simulation scenario is conducted on a virtual MTR station, where parameter settings are discussed and some regular phenomena helpful to the designers of stations is put forward.
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Zhou, Wenju, Fulong Yao, Wei Feng et Haikuan Wang. « Real-Time Height Measurement for Moving Pedestrians ». Complexity 2020 (27 août 2020) : 1–15. http://dx.doi.org/10.1155/2020/5708593.
Texte intégralRésumé :
Height measurement for moving pedestrians is quite significant in many scenarios, such as pedestrian positioning, criminal suspect tracking, and virtual reality. Although some existing height measurement methods can detect the height of the static people, it is hard to measure height accurately for moving pedestrians. Considering the height fluctuations in dynamic situation, this paper proposes a real-time height measurement based on the Time-of-Flight (TOF) camera. Depth images in a continuous sequence are addressed to obtain the real-time height of the pedestrian with moving. Firstly, a normalization equation is presented to convert the depth image into the grey image for a lower time cost and better performance. Secondly, a difference-particle swarm optimization (D-PSO) algorithm is proposed to remove the complex background and reduce the noises. Thirdly, a segmentation algorithm based on the maximally stable extremal regions (MSERs) is introduced to extract the pedestrian head region. Then, a novel multilayer iterative average algorithm (MLIA) is developed for obtaining the height of dynamic pedestrians. Finally, Kalman filtering is used to improve the measurement accuracy by combining the current measurement and the height at the last moment. In addition, the VICON system is adopted as the ground truth to verify the proposed method, and the result shows that our method can accurately measure the real-time height of moving pedestrians.
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Lu, Yining, Tao Wang, Zhuangzhuang Wang, Chaoyang Li et Yi Zhang. « Modeling the Dynamic Exclusive Pedestrian Phase Based on Transportation Equity and Cost Analysis ». International Journal of Environmental Research and Public Health 19, no 13 (4 juillet 2022) : 8176. http://dx.doi.org/10.3390/ijerph19138176.
Texte intégralRésumé :
The exclusive pedestrian phase (EPP) has proven to be an effective method of eliminating pedestrian–vehicle conflicts at signalized intersections. The existing EPP setting conditions take traffic efficiency and safety as optimization goals, which may contribute to unfair interactions between vehicles and pedestrians. This study develops a multiobjective optimization framework to determine the EPP setting criteria, with consideration for the tradeoff between transportation equity and cost. In transportation equity modeling and considering environmental conditions, the transportation equity index is proposed to quantify pedestrian–vehicle equity differences. In cost modeling, traffic safety and efficiency factors are converted into monetary values, and the pedestrian–vehicle interaction is introduced. To validate the proposed optimization framework, a video-based data collection is conducted on wet and dry environment conditions at the selected intersection. The parameters in the proposed model are calibrated based on the results of the video analysis. This study compares the performance of the multiobjective evolutionary algorithm based on decomposition (MOEA) and the nondominated sorting genetic algorithm II (NSGA-II) methods in building the sets of nondominated solutions. The optimization results show that the decrease in transportation equity will lead to an increase in cost. The obtained Pareto front approximations correspond to diverse signal timing patterns and achieve a balance between optimizing either objective to different extents. The sensitivity analysis reveals the application domains for the EPP and the traditional two-way control phase (TWC) under different vehicular/pedestrian demand, yielding rate, and environment conditions. The EPP control is more suitable at intersections with high pedestrian volumes and low yielding rates, especially in wet conditions. The results provide operational guidelines for decision-makers for properly selecting the pedestrian phase pattern at signalized intersections.
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Nimac, Peter, Andrej Krpič, Boštjan Batagelj et Andrej Gams. « Pedestrian Traffic Light Control with Crosswalk FMCW Radar and Group Tracking Algorithm ». Sensors 22, no 5 (23 février 2022) : 1754. http://dx.doi.org/10.3390/s22051754.
Texte intégralRésumé :
The increased mobility requirements of modern lifestyles put more stress on existing traffic infrastructure, which causes reduced traffic flow, especially in peak traffic hours. This calls for new and advanced solutions in traffic flow regulation and management. One approach towards optimisation is a transition from static to dynamic traffic light intervals, especially in spots where pedestrian crossing cause stops in road traffic flow. In this paper, we propose a smart pedestrian traffic light triggering mechanism that uses a Frequency-modulated continuous-wave (FMCW) radar for pedestrian detection. Compared to, for example, camera-surveillance systems, radars have advantages in the ability to reliably detect pedestrians in low-visibility conditions and in maintaining privacy. Objects within a radar’s detection range are represented in a point cloud structure, in which pedestrians form clusters where they lose all identifiable features. Pedestrian detection and tracking are completed with a group tracking (GTRACK) algorithm that we modified to run on an external processor and not integrated into the used FMCW radar itself. The proposed prototype has been tested in multiple scenarios, where we focused on removing the call button from a conventional pedestrian traffic light. The prototype responded correctly in practically all cases by triggering the change in traffic signalization only when pedestrians were standing in the pavement area directly in front of the zebra crossing.
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Li, Yong, Guofeng Tong, Xin Li, Yuebin Wang, Bo Zou et Yujie Liu. « PARNet : A Joint Loss Function and Dynamic Weights Network for Pedestrian Semantic Attributes Recognition of Smart Surveillance Image ». Applied Sciences 9, no 10 (16 mai 2019) : 2027. http://dx.doi.org/10.3390/app9102027.
Texte intégralRésumé :
The capability for recognizing pedestrian semantic attributes, such as gender, clothes color and other semantic attributes is of practical significance in bank smart surveillance, intelligent transportation and so on. In order to recognize the key multi attributes of pedestrians in indoor and outdoor scenes, this paper proposes a deep network with dynamic weights and joint loss function for pedestrian key attribute recognition. First, a new multi-label and multi-attribute pedestrian dataset, which is named NEU-dataset, is built. Second, we propose a new deep model based on DeepMAR model. The new network develops a loss function, which joins the sigmoid function and the softmax loss to solve the multi-label and multi-attribute problem. Furthermore, the dynamic weight in the loss function is adopted to solve the unbalanced samples problem. The experiment results show that the new attribute recognition method has good generalization performance.
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Zhao, Rongyong, Ping Jia, Yan Wang, Cuiling Li, Chuanfeng Han et Zhishu Zhang. « Dynamic model of macro crowd merging based on abnormal pedestrian posture ». MATEC Web of Conferences 355 (2022) : 03009. http://dx.doi.org/10.1051/matecconf/202235503009.
Texte intégralRésumé :
Crowd merging is a complex process, and any sudden external or internal disturbance will destroy the stability of the crowd. The occurrence of abnormal behavior will affect the crowd flow process and inevitably affect the stability of the crowd flow system. The position information of the joint points is obtained through the OpenPose algorithm, and the kinematics characteristics of each node are studied. It is judged whether the number of pedestrians in the crowd and the scale of the building scene are greater than the empirical setting value based on engineering statistical data and expert experience. When the number of pedestrians is more than 2,000 and the total area of the passage is more than 2,000 square meters, the appropriate macro-dynamic model is selected. The Aw-Rascle (AR) fluid dynamics model is selected in this study. The joint point information obtained through the OpenPose is combined with the macroscopic fluid dynamics model to construct a macroscopic crowd flow dynamics model based on the pedestrian's abnormal posture.
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Luo, Hongbin. « Pedestrian Reidentification Based on Feature Fusion and Metric Learning ». International Journal of Circuits, Systems and Signal Processing 16 (5 janvier 2022) : 105–14. http://dx.doi.org/10.46300/9106.2022.16.14.
Texte intégralRésumé :
The pedestrian recognition in public environment is influenced by the pedestrian environment and the dynamic characteristic boundary factors, so it is easy to produce the tracking error. In order to improve the ability of pedestrian re-identification in public environment, we need to carry out feature fusion and metric learning, and propose pedestrian re-identification based on feature fusion and metric learning. The geometric grid area model of pedestrian recognition in public environment is constructed, the method of fuzzy dynamic feature segmentation is used to reconstruct the dynamic boundary feature point of pedestrian recognition in public environment, the method of bottom-up modeling is used to design the dynamic area grid model of pedestrian recognition in public environment, the design of dynamic area grid model is three-dimensional grid area, the grayscale pixel set of pedestrian recognition dynamic constraint under public environment is extracted, the boundary feature fusion is carried out according to the distribution intensity of grayscale, the image fusion and enhancement information processing of pedestrian recognition under public environment, and the method of 3D dynamic constraint is used to realize the local motion planning of pedestrian recognition under public environment, and the recognition feature fusion and learning of pedestrian recognition under public environment is realized according to the result of contour segmentation. The simulation results show that the method is used for pedestrian recognition again in public environment, and the fuzzy judgment ability of pedestrian dynamic edge features is strong, which makes the error controlled below 10 mm, and the fluctuation of pedestrian recognition again is more stable, the recognition accuracy is higher and the robustness is better.
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Newl, D. E. « Pedestrian excitation of bridges ». Proceedings of the Institution of Mechanical Engineers, Part C : Journal of Mechanical Engineering Science 218, no 5 (1 mai 2004) : 477–92. http://dx.doi.org/10.1243/095440604323052274.
Texte intégralRésumé :
This paper reviews the evidence on dynamic bridge loading caused by moving pedestrians. The phenomenon of ‘synchronization’ by which people respond naturally to an oscillating bridge when this has a frequency close to their natural walking or running frequency is a feature of this phenomenon. By increasing modal damping, synchronization can be prevented, but how much damping is needed in any particular situation? If some simplifying assumptions about how people walk are made, it is possible to predict analytically the minimum damping required to ensure that synchronization does not lead to high vibration levels. The main assumption is that the movement of a pedestrian's centre of mass has two components. One is its natural movement when the person is walking on a stationary pavement. The other is caused by movement of the pavement (or bridge) and is in proportion to pavement amplitude but with a time delay that is arbitrary. When the time delay is a ‘worst case’, pedestrians act as a source of negative damping. This theory supports the adoption of a non-dimensional number which measures the susceptibility of a bridge to pedestrian excitation. Although currently there are not many good bridge response data, predictions using this non-dimensional number are compared with the data that are available and found to be in satisfactory agreement. Both lateral and vertical vibrations are considered.
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Gao, Yan-an, et Qing-shan Yang. « A Theoretical Treatment of Crowd–Structure Interaction ». International Journal of Structural Stability and Dynamics 18, no 01 (janvier 2018) : 1871001. http://dx.doi.org/10.1142/s0219455418710013.
Texte intégralRésumé :
A vertical crowd–structure interaction model including the interaction amongst pedestrians is developed to study the structural performances of the supporting structure with social force effect. This model can be used to analyze the vibration problem of footbridge under a large crowd excitation. The social force is firstly introduced to describe the dynamic interaction amongst the bipedal models with damping-spring legs modeling pedestrian movement on a three-dimensional plate structure. The social force determines the walking direction and velocity of pedestrian. Numerical studies show that the structural dynamic performances can be remarkably changed under the crowd action. The natural frequency of structure is decreased and is time-varying with an increase in the crowd density. However, the damping ratio of structure is increased. The proposed model could well describe the crowd–structure dynamic interaction.
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Liu, Wenjun, Aowen Duan, Kui Li, Jinlong Qiu, Liangfei Fu, Hongchun Jia et Zhiyong Yin. « Parameter sensitivity analysis of pedestrian head dynamic response and injuries based on coupling simulations ». Science Progress 103, no 1 (23 décembre 2019) : 003685041989246. http://dx.doi.org/10.1177/0036850419892462.
Texte intégralRésumé :
There are a very limited number of reports studying on the dynamic response and injuries of pedestrian head in the scenarios with head hitting windshield. This study aims to investigate the significant factors that affect the dynamic response and injuries of pedestrian head through finite element–multi-body coupling simulations. Two finite element vehicle models and two multi-body pedestrian human models were used to build the coupling simulations. Orthogonal experimental design and analysis of variance were used for parameter combination and data analysis. This study demonstrated that the dynamic response of pedestrian head and HIC15 were strongly associated with collision speed and pedestrian orientation. Vehicle type had a significant influence on the dynamic response of pedestrian head and HIC15, while there was no significant relationship between the dynamic response of pedestrian head and HIC15 and the size of pedestrian human models. Collision speed, pedestrian orientation, and vehicle type should be prioritized over the other collision parameters in the study of head injury mechanism and reconstruction of vehicle–pedestrian collisions in the scenarios with head hitting windshield.
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Luo, Wei, Pengpeng Jiao et Yi Wang. « Pedestrian Arching Mechanism at Bottleneck in Subway Transit Hub ». Information 12, no 4 (11 avril 2021) : 164. http://dx.doi.org/10.3390/info12040164.
Texte intégralRésumé :
Under the massive pedestrian flow, pedestrians arching phenomenon forms easily at bottleneck in subway hubs, which might stampede and crush. To explore pedestrian arching mechanism at bottleneck in subway transit hub, this paper conducts a series of simulation experiment. Firstly, movement preference characteristic in subway transit hubs was introduced into the social force model which considers multiple force. Then, after setting basic experiment scenario, unidirectional flow at different bottlenecks were simulated. Finally, the mechanism of pedestrian arching phenomenon at bottleneck was quantitative analyzed with the help of experimental data. Some main conclusions are summarized. Pedestrian arching phenomenon could be divided into four stages: Free, arching formation, arching stabilization and arching dissipation. In addition, the relationship between bottleneck scenario and passing time could be built to a function model. With the different of bottleneck width ratio, passing time presents positive correlation. The research results could give some helps for understanding the dynamic evolution process of unidirectional flow at bottleneck, improving the pedestrian efficiency at bottleneck and optimizing pedestrian facilities in subway transit hub.
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Peter Chol, Duom. « SIMULATION OF CAR-PEDESTRIAN CRASH : INJURY ASSESSMENT AND IMPACT POSITIONS ». International Journal of Advanced Research 10, no 11 (30 novembre 2022) : 345–51. http://dx.doi.org/10.21474/ijar01/15677.
Texte intégralRésumé :
In car-pedestrian collisions, pedestrian fatal injuries account for a great number of health risks in the world. A real-world accident case with a medical examination record would improve the reliability of simulation of car-pedestrian accidents but is rarely captured. The goal of this report was to assess the pedestrian injuries, and impact positions. A case of a pedestrian impacted by a car traveling at a speed of 22 km/hr was simulated using the MAthematical DYnamic MOdel (MADYMO) program. The results showed that Abbreviated Injury Score one (AIS1) head injury and Abbreviated Injury Score two (AIS2) toe fracture are caused by pedestrian impact with windshield and wheel. The maximum head linear acceleration and right foot force that led to head injuries and toe fractures are 1688.61 m/s2 and 15799.00 N, respectively. The results obtained in terms of head impact location, left forearm impact, and the right foot impact positions are comparable with the real-world road accident. This report can help in the future design of automobiles that are friendly to vulnerable pedestrians.
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Hartmann, Dirk, et Peter Hasel. « Efficient Dynamic Floor Field Methods for Microscopic Pedestrian Crowd Simulations ». Communications in Computational Physics 16, no 1 (juillet 2014) : 264–86. http://dx.doi.org/10.4208/cicp.200513.290114a.
Texte intégralRésumé :
AbstractFloor field methods are one of the most popular medium-scale navigation concepts in microscopic pedestrian simulators. Recently introduced dynamic floor field methods have significantly increased the realism of such simulations, i.e. agreement of spatio-temporal patterns of pedestrian densities in simulations with real world observations. These methods update floor fields continuously taking other pedestrians into account. This implies that computational times are mainly determined by the calculation of floor fields. In this work, we propose a new computational approach for the construction of dynamic floor fields. The approach is based on the one hand on adaptive grid concepts and on the other hand on a directed calculation of floor fields, i.e. the calculation is restricted to the domain of interest. Combining both techniques the computational complexity can be reduced by a factor of 10 as demonstrated by several realistic scenarios. Thus on-line simulations, a requirement of many applications, are possible for moderate realistic scenarios.